ENERGY: Lack of coordination led to blackout, feds say

A lack of information-sharing among electricity regulators and an overly conservative circuit-breaker design at the San Onofre Nuclear Generating Station were what left 2.7 million homes and businesses in the dark on Sept. 8, said
a report
released by federal regulators Tuesday.

The blackout, which spread across San Diego and Imperial counties and parts of Arizona, Mexico, and Orange County, was the largest American power failure since 55 million people lost power in the 2003 blackout in the northeastern United States. The September power failure began when a worker error in Arizona caused a major transmission line to disconnect.

A long-standing failure to share information across the web of utilities and regulating agencies came to a head the day of the blackout, the report said. As transformers and generators clicked off one by one in Imperial County, a surge of power flowed through San Diego County's grid, headed north past San Onofre. But the tolerances on the switches on those lines, which are analogous to breaker switches in a house, were set too low, and they disconnected San Diego unnecessarily, the report said.

"We ran simulations, and (the blackout) would not have been worse if the (San Onofre plant disconnect) scheme had not operated," said Heather Polzin, an attorney with the FERC office of enforcement, and the agency's lead on the report.

The report did not include any findings of fault, nor did it include whether anyone was being investigated for failing to meet reliability standards. However, the
Western Electric Coordinating Council
, the agency responsible for enforcing electricity reliability standards for 14 states and two Canadian provinces, received the most recommendations for changes proposed in the report.

"We were not given an advance copy of the report, and we're still reviewing it," said
Kathi VanderZanden
, a spokeswoman for WECC.

As for criminal investigations, FERC's Polzin said all investigations are confidential until a commission vote. If any utilities or agencies are found at fault, they could face millions of dollars in fines.

The blackout was an unusually complicated affair. Electricity supply and demand in the area was managed by five organizations, called "balancing authorities." Information sharing between these agencies has been a longstanding problem, said Stephen Berberich, CEO of the California Independent System Operator, the balancing authority for SDG&E, Pacific Gas & Electric Co., and Southern California Edison.

"The fact that information needed to be better exchanged in the West is not a new issue," he said.

The communications and information-sharing problems emerged before the blackout even began. Berberich's organization, ISO, had reported a planned outage of a 600-megawatt power plant in Baja California, Mexico, that fed into the Southern California grid, but none of the other operators seemed to be aware of it, the FERC report said. That loss of generation, combined with a hot day, meant the local grid was already in a precarious state before the transmission line cut out.

At 3:27 p.m., a worker for Arizona Public Service failed to disconnect some equipment properly at a substation near Yuma, Ariz., the report said. His error led to the disconnection of the Southwest Powerlink, one of only two electric transmission pathways leading into or out of San Diego County.

The disconnect caused a power surge into parts of Arizona, Imperial County, and San Diego County. That surge drove a cascade of transformer failures in the Imperial Irrigation District, which is both the utility and balancing authority for Imperial County. Those disconnections were not visible in real time to operators for San Diego Gas & Electric Co., nor to those for the ISO. As a result, none of those agencies could act to forestall the problems, the report said.

As transformers tripped off, more and more electricity was funneled through San Diego County and north past San Onofre into Orange County.

Kevin Kelley, general manager for the Imperial Irrigation District, rejected any claim that his agency's equipment exacerbated the blackout.

"Based on what has been learned to date, not only through its own internal review, but via a parallel assessment done by an independent consultant, the district fundamentally rejects any assertion that its relay operations to protect its transformers from damage led to the cascading effect associated with the Sept. 8 outage," Kelly said in a written statement.

Within 10 minutes of the first failure, at 3:37 p.m., current flowing over power lines running north past San Onofre had exceeded a designed maximum tolerance of 8,000 amps, and the lines disconnected from the south. When that happened, San Onofre's turbines disconnected from the grid, causing a sudden power drop in south Orange County as well as San Diego, plunging both areas into darkness.

But it wasn't technologically necessary for those lines to switch off, the report said. They could have remained working safely, and thus mitigated much of the power failure in the region, the report said.

Southern California Edison, which has majority ownership in San Onofre, said the switch-off plan was 30 years old.

"Before the September separation occurred, more than 30 unusual events had jeopardized system stability in the West," Edison said in a written statement. "When the separation between SCE's and San Diego Gas & Electric's systems occurred, the safety net design operated exactly as planned and protected against outages in SCE's service territory and possibly beyond."

In his own response to the report, Mike Niggli, SDG&E's chief operating officer, promised to begin working on the recommendations immediately, according to SDG&E's Twitter account.